Bridge construction



Marh 24, 1959 J. D. GoLLNow 2,878,498

BRIDGE CONSTRUCTION Filed June 28', 1954 5 Sheets-Sheet 1 Ma'rch 24,1959 J. D. GoLLNoW BRIDGE CONSTRUCTION 3 Sheets-Sheet 2 Filed June 28,1954 Mardi 24, 1959- J, Dl GQLLNQW 2,878,498.

. BRIDGE CONSTRUCTION Filed June 28. 1954 Tur?. 2/

` :s sheets-sheet 3 nited States BRIDGE CONSTRUCTION Johannes DieterGollnow, Dusseldorf-Oberkassel, Germany, assignor to Gollnow-Werke A.G., Dusseldorf, Germany The present invention relates to supportingstructures generally, and more particularly to bridges and a new methodof erecting the same.

It is one of the objects of the invention to design a new bridgestructure, and especially one for relatively great span lengths, whichcan be erected very quickly and at a low cost both in labor andmaterial.

Another object of the invention is to erect a bridge of relatively greatsolidity and load capacity, and without any of the usual preliminarysupporting structures which under previous bridge building methods firsthad to be erected and later removed at a considerable expense and wasteof time, and which usually could not be used again for subsequentconstructions.

Consequently, it is an important object of the invention to erect abridge with the aid of only a few accessories and materials which,moreover, after they have accomplished their purpose during thiserection, may be easily dismantled or removed for subsequent use in theerection of another bridge.

Another object of the invention resides in a new method of erecting abridge or similar supporting structure of a permanent nature by means ofmaterials and accessories which are of light weight and easilytransportable.

More specifically, it is an object and a feature of the invention toerect a bridge, and particularly one of considerable length, Very easilyand quicky, and by the mere use of a supporting cable for spanning theriver or ravine and serving as the main support of the bridge during itserection, and only a few auxiliary anchorage means and otheraccessories, all of which are easily and quickly put up for the erectionof the bridge and again quickly removed for building another bridge orsimilar structure.

For these reasons, the invention is particularly adapted not only forthe erection of bridges for normal civilian traflic but also formilitary use where the quick erection of a reliable bridge spanpossiblyeven under enemy fire-may be the key to victory.

Although chiefly concerned with the erection of bridges, the presentinvention is, however, not limited thereto. Thus, for example, theframework designed according atent O to the invention, and the speedyand inexpensive method and the new method of erecting the same by meansof A non-rigid and noncompressive girders or trusses, such as cableropes and the like, so that thse cable ropes constitute the main supportofthe final bridge or similar structure.

f I 1C@ Further objects, features, and advantages of the invention willappear from the following detailed description thereof and theaccompanying drawings, in which Fig. l shows diagrammatically a cableframe designed and erected according to the invention, and forming oneof the spans of a bridge;

Figs. 2 and 3 show two ditferent stages in the erection of a suspensionor supporting frame as illustrated in Fig. 1;

Figs. 4 and 5 show two different stages in the erection of a bridgeaccording to a modification of the invention;

Fig. 6 illustrates another embodiment of the invention, and shows abridge substantially completed;

Fig. 7 is an enlarged side View of a vertical supporting beam with atrolley wheel used in the erection of the new bridge; while Fig. 8 is afront view of the trolley shown in Fig. 7.

Referring to the drawings, Fig. l diagrammatically illustrates an openweb girder or suspension frame consisting of upper and lower chords 1and 2, and diagonal struts 3 secured thereto, all of them preferablyconsisting of steel cables of a strength depending upon the length ofthe bridge and its required load capacity. In the central part of thespan, the diagonal struts 3 cross each other, while toward both endsthey extend in the same direction so as better to take up the transverseforces. The vertical supporting beams 4 consist of rigid elements. Theentire suspension frame rests upon bridge portals 5 which, in turn, areanchored in foundation blocks 6. The upper chord 1 is held under tensionby guy ropes 7.

A complete bridge will consist of two or more suspension frames of thetype described which may be braced relative to each other in anysuitable manner, and between which the bridge roadway may be built, foreX- ample, `011 the level of the lower chords 2. For reasons of a betterillustration of the invention, the roadway has not been specically shownin the drawings.

Fig. 2 shows a bridge according to the invention under construction andillustrates the new method of erecting it, in which the suspension frameis iirst being assembled in a collapsed position at one side of thebridge site and then pulled across the entire river or ravine to bespanned.

For this purpose, the portals 5 are rst erected on the foundation blocks6, and an erection cable 11 is then layed over the portals andtemporarily anchored on both sides. If it is not readily possible tocross the ravine or river, a lead line may rst be shot from one side tothe other and then used to draw the erection cable 11 across the site.One of the portals 5 from the point of which the erection is to takeplace is preferably provided with working platforms or scaifolds 12which, when no longer needed, may be removed. For assembling thesuspension frame, one of the beams 4 is raised up, for example, by meansof a light derrick 18 mounted on the tip of the portal 5, and suspendedon a trolley wheel 13 which is adapted to roll along the erection cable11. Then, the diagonal struts 3 and the upper and lower chords 1 and 2will be secured at the respective truss joints. Since all these elementsconsist of wire ropes, they may remain during the assembly in a slack orcollapsed condition. A traction rope 15 as well as a backstay rope 16are then secured to the iirst truss joint 14 in which the lower chord 2,one diagonal strut 3, and the upper chord 1 intersect, and whichsubsequently is secured to the opposite portal 5'. Both ropes 15 and 16lead to Winches 8 and 9 at the opposite sides or at both sides of theriver or ravine to be bridged.

The upper and lower chords 1 and 2 may either consist of individualpieces which are secured to the respective truss joints by means ofcable clamps, or they may extend clear across the entire bridge span, inwhich case l they may be rolled up on drums 17 and unrolled therefromstep by step as the suspension frame is being assembled and the tractionrope 15 tightened to draw the truss joint 14 further across when thenecessary connections on one vertical beam 4 have been completed.

Fig. 3 illustrates the same bridge building site in a stage ofconstruction when the individual elements of the suspension frame havebeen completely assembled but when all those elements which consist ofwire rope are still in a slack condition, and the vertical beams 4 arestill relatively close together and not drawn apart to their propertinal spacing. The suspension frame is then drawn entirely across theentire bridge span by means of the traction rope 15and the latter isthen drawn taut so that the upper and lower chords 1 and 2 will have thenecessary final tension and the entire suspension frame will be liftedfrom the erection cable 11. After guy ropes or braces 7 have beensecurely anchored and the erection cable 11 as well as the trolleywheels 13 have been dismounted, the suspension frame will have attainedits final shape, as illustrated in Fig. l.

After thus erecting the first main suspension frame of the bridge, thesecond frame as well as any additional supporting frames may then beerected and secured in the same manner. With the main supporting framesonce being erected, it will then be a relatively easy matter to installthe other essential parts of the bridge, such as portal and lateralbraces and the like, as well as crossbeams, treadways or stringers, andother elements necessary for building a permanent roadway thereon.Depending upon the particular position of the site, such roadway mayeither be mounted on the level of the upper chords 1, the lower chords2, or any intermediate level.

Figs. 4 and 5 illustrate a modification of the invention in which, asidefrom the portals 105 and 105', an auxiliary portal or upright 131 isprovided at such a distance from the main portal 105 so as to leavesuflicient intermediate space to assemble the individual elements of thesuspension frame in a slack or collapsed position. Thus, in thisembodiment of the invention, the main suspension frame will be assembledoutside of the actual bridge span. A preferred method of erecting thebridge consists in rst completely assembling and mounting the mainsuspension frame atly on the ground in the space intermediate theauxiliary portal 131 and the main portal 105, including the connectionof the trolley wheels 113 to the beams 104. The erection cable 111,which is stretched across the river or ravine to be bridged and placedon the tip of the portals 105 and 105 in the manner as previouslydescribed relative to Figs. 2 and 3, is then first temporarily securedto a suitable post or bracket laterally of the portal 105, whereupon itis threaded on the ground through the trolley wheels which are mountedon beams 104, and then layed over the auxiliary portal 131 and connectedto the winch 132. When the erection cable 111 is then being tightened bymeans of the winch 132, the entire suspension frame, still in a slack orcollapsed position, will gradually be raised from the ground, asillustrated in Fig. 4, in which some of the beams 104a have already beenpartly raised, while those toward the middle between the portals 105 and131 are still resting on the ground. When the erection cable 111 isfurther tightened by means of the winch 132, the entire suspension framewill be raised and brought into the position illustrated in Fig. 5.Thereafter, as previously described relative to Figs. 2 and 3, thetraction rope 115 will be tightened by means of the winch S and thesuspension frame drawn past the portal 105, with the trolley wheels 113rolling along the erection cable 111, and entirely across the span,whereupon the traction rope will be drawn taut so that the suspensionframe will become substantially selfsupporting. The necessary guy ropesare then secured and tightened, and the erection and traction cables 111and 115 aswell as the trolley wheels 113 and the otheraccessories suchas the auxiliary portal 131 and the Winches 108 and 132 may then beremoved.

In order to illustrate the applicability of the new method of bridgebuilding to suspension or supporting frames of various designs, adifferent type of open web design or latticework has been used toconstruct the frame shown in Figs. 4 and 5 than that used in Figs. l to3. However, as in Figs. 1 to 3, a steel cable may also be used for theupper supporting chord.

If, however, for certain reasons the upper chord should only be placedunder tension during the erection of the bridge, while in the nalcondition such special anchorage of the upper chord should be dispensedwith, a different bridge design, as illustrated in Fig. 6, may befollowed. After erecting the suspension frame or frames, as describedrelative to Figs. 2 to 5, an upper chord or beam of rigid sections 241will then be installed. Since the respective road gap has already beenbridged by the suspension frame, such installation will be an easymatter. This may be done, for example, by advancing the individual beamsections 241 by means of suitable rollers or trolleys along the regularchord cable and securing them at the truss joints to the vertical beams104. The following beam sections 241 may then be rolled forwardly alongthose already in place and secured to the next vertical beam. After theentire horizontal beam has been completed and secured, the guy ropes,such as shown in Fig. l, may be loosened and removed. The beam sections241 may also be successively installed prior to the removal of theerection Icable by suspending the first section on hoists or trolleys onsuch cable, and rolling it along the same to the proper position andthen mounting it on the rst vertical beam. The following sections 241may then either be hoisted in the same manner to their proper position,or they may be moved there by sliding them along the sections already inplace.

Fig. 7 shows on an enlarged scale a side view of a vertical beamtogether with the upper and lower truss joints and the trolley wheel, as-applied in the bridge constructions shown in Figs. 1 to 6, while Fig. 8shows a front view of the upper half thereof. The vertical beam 204 ofany suitable cross sectional shape has secured to its upper end a pairof fishplates 221 and to its lower end a pair of iishplates 222. Bothpairs of plates have bores 223 in which either the bolts for securingthe upper and lower chords or the diagonal struts are mounted as desiredin the particular instance. The upper shplates 221 have additional bores224 for mounting the yokes 225 in which the trolley wheels 213 arerotatably supported. The yokes 225 are open on one side so that they maybe easily placed upon the erection cable 211. After the suspension framehas been fixed in place and properly secured, the yokes and wheels areremoved. lf, as shown in Fig. 6, a rigid upper chord or beam 241 is tobe installed after the suspension frame as such has been secured inplace, the bores 224 will then be utilized for mounting the beamsections or bolting them to each other as well as to the vertical beams204. In the particular embodiment of the invention as illustrated inFigs. 7 and S, the upper chord cable 201 and the lower chord cable 202consist of individual sections which are connected by twin cable clamps226 and 227, respectively. The bores provided in these clamps are usedfor bolting them to the fishplates 221 and 222, respectively.

The inventive design of the suspension frames permits the application oftension and compression members of various types. The tension membersmay, for example, consist of ropes or cables of various types or ofchains, while the compression members may be of tubular construction, ofnormal steel of at or angular cross section, of wood, reinforcedconcrete, light metal, or other suitable materials.

The individual suspension frames may also be made of parabolic,parallel-truss, or other shape customary in bridge superstructures. Ifdesired, and especially when asesinas used on steep embankments, theupper chord thereof may also be rested and secured directly upon'theabutments without the use of any portals. A bridge consisting ofsuspension or supporting frames of the type as described may, withoutchange of its individual members, also be adapted to various loadcapacities or different span lengths by making the main frames ofsingle, double, or triple walls, depending upon the particularrequirements in each case, or by making the individual frames of asingle floor type as shown in Fig. 6, or a double floor type, as shownin Fig. l.

If the bridge building site is such that the terrain between the twoportals is easily accessible and a light, or possibly a oating, trestlemay be built or placed within the span to be bridged so that the slackor collapsed suspension frame may be assembled thereon, the auxiliaryportal 131 as well as the erection cable may then be dispensed with. Thetraction ropes will then vbe secured on both sides directly to the firstand last truss joints 14 and 21 of the upper chord and layed over theportals, and the suspension frame will then be pulled up directly andtightened until the two outer ends of the upper chord will rest upon theportals.

The suspension frames according to the invention and the new method oferecting a bridge may be applied with particular advantage if the bridgeto be built has to span several successive ravines or other breaks inthe surface of the terrain. The suspension frames will then be connectedtogether at their upper chords, and the outwardly directed tension tosolidify the individual frames need only be applied to the outer ends ofthe entire string of bridges. v

The simplicity with which the suspension frame may be manipulated andthe low weight thereof permit its application and the application of thenew method not only to the erection of bridges but also to the use ofsuch frames as supporting structures for large halls, hangars, or thelike, or as scaffolds or for similar puroses. p While the foregoingdescription sets forth in detail what I regard as the preferredlembodiments `of my invention, it is to be understood that numerouschanges may be made therein without departing from the spirit and scopeof the invention as defined in the appended claims.

Having thus described my invention, what I claim as new is:

ll. A method of erecting a frame structure for a bridge comprising aframe consisting of upper and lower flexible chords, rigid verticalbeams intermediate said chords, and diagonal flexible struts connectingysaid flex ible chords and vertical beams, comprising the steps ofstretching a cable across the gap to be bridged, assembling theindividual elements of said frame on the ground in a collapsed conditionwith the beams closely adjacent each other and interconnecting thediagonal struts with the flexible chords and arranging the assembly withthe chords in a slack condition, attaching trolleys to one end of eachof said beams, raising the elements of said frame in a successive orderand gradually suspending said trolleys on said cable with the beams invertical position, applying a traction on the outer end of the upperchord facing the gap and simultaneously releasing the other end thereofso as to draw the slack frame on said trolleys along said cable,securing the other end of said upper chord, applying further traction onsaid first outer chord end so as to spread apart the individual elementsof said frame, drawing said upper chord taut and anchoring it in a fixedposition, and removing said cable and trolleys from said frame.

2. A method of erecting a bridge comprising at least two frames, eachconsisting of upper and lower ilexible chords, rigid vertical beamsintermediate said chords, and diagonal flexible struts connecting saidflexible chords and vertical beams, comprising the steps of stretching acable across the gap to be bridged, assembling the individual elementsof said frame on the ground in a collapsed condition with the beamsclosely adjacent each other and the flexible chords and diagonal strutsin a slack condition, attaching trolleys to one end of each of saidbeams, raising the elements of said frame in a successive order andgradually suspending said trolleys on said cable with the beams invertical position, applying a traction on the outer end of the upperchord facing the gap and simultaneously releasing the other end thereofso as to draw the slack frame on said trolleys along said cable,securing the other end of said upper chord, applying further traction onsaid first outer chord end so as to spread apart the individual elementsof said frame, drawing said upper chord taut and anchoring it in a fixedposition, removing said trolleys from said frame and cable, hoisting arigid horizontal beam section from one end of said frame along saidcable and mounting it on the first intersection of the upper chord withthe rst vertical beams and diagonal strut, moving a second rigidhorizontal beam section along said first section and mounting it on thesecond intersection, and successively sliding other beam sections alongthose already mounted into their respective place and successivelymounting the same on the following intersections until a rigidhorizontal beam extends across the gap to be bridged, and iinallyremoving said cable.

3. A method of erecting a bridge comprising at least two frames andconsisting of upper and lower exible chords, rigid vertical beamsintermediate said chords, and diagonal flexible struts connecting saidflexible chords and vertical beams, comprising the steps of stretching acable across the gap to be bridged, assembling the individual elementsof said frame on the ground in a collapsed condition with the beamsclosely adjacent each other and the flexible chords and diagonal strutsina slack condition, attaching trolleys to one end of each of saidbeams, raising the elements of said frame in a successive order and`gradually suspending said trolleys on said cable with the beams invertical position, applying a traction on the outer end of the upperchord facing the gap and simultaneously releasing the other end thereofso as to draw the slack frame on said trolleys along said cable,securing the other end of said upper chord, applying further traction onsaid first outer chord end so as to spread apart the individual elementsof said frame, drawing said upper chord taut and anchoring it in a fixedposition, removing said trolleys from said frame and cable, suspending arigid horizontal beam section on said cable, hoisting it to the firstintersection of the upper chord with the first vertical beam anddiagonal strut, and securing it to said intersection, and successivelyhoisting other beam sections along said cable to the followingintersections and securing them thereto until a rigid horizontal beamextends across the gap to be bridged, and finally removing said cable.

4. A method of erecting a bridge comprising at least two frames, eachconsisting of upper and lower flexible chords, rigid vertical beamsintermediate said chords, and diagonal flexible struts connecting saidflexible chords and vertical beams, comprising the steps of mounting atleast one pair of portals on each side of the gap to be bridged,extending an erection cable across the gap and over the upper ends oftwo corresponding opposite portals, and tightening said cable,assembling the individual elements of one frame on the ground in acollapsed condition with the rigid beams closely adjacent each other andthe flexible chords and diagonal struts in a slack condition, hoistingsuccessive elements of said frame to an upright position and attachingthem successively to the erection cable with the vertical beams stillrelatively closely adjacent each other and the upper and lower chordsand diagonal struts in a slack condition, spreading the frame membersapart and tautly across the gap and securing the outer ends of theupperchord in a xed position on the ground, removing the erection cable,erecting the second frame in the same manner as said first frame, andbracing both frames relative to each other and to the ground.

5. A method of erecting a bridge comprising at least two frames, eachconsisting of upper and lower flexible chords, rigid vertical beamsintermediate said chords, and diagonal llexible struts connecting saidlleXible chords and vertical beams, comprising the steps of mounting atleast one pair of portals on each side of the gap to be bridged and atleast one upright of substantially the same height as said portals onone side of the gap and spaced from one of the portals on that side,extending an erection cable across the gap and over the upper ends oftwo corresponding opposite portals and said upright, tightening saidcable intermediate said portals but leaving the cable portionsubstantially slack between said upright and the adjacent portal,assembling the individual elements of one frame on the groundintermediate the upright and the adjacent portal, and in a collapsedcondition with the rigid beams closely adjacent each other and theflexible chords and diagonal struts in a slack condition, attachingtrolleys to one end of each of said beams, attaching all of saidtrolleys to said cable portion, tightening said cable portion at thefree outer end thereof adjacent said upright and there by graduallyraising the entire frame from the ground, rolling the frame on saidtrolleys past the adjacent portal and spreading the adjacent frameelements apart intermediate said portals above said gap, drawing theouter ends of the upper chord taut and securing said ends in a fixedposition on the ground, removing the trolleys, the erection cable, andupright, erecting the second frame in the same manner as said rst frame,and bracing both frames relative to each other and to the ground.

6. A method of erecting a bridge comprising at least two frames, eachconsisting of upper and lower exible chords, rigid vertical beamsintermediate said chords, and diagonal exible struts connecting saidflexible chords and vertical beams, comprising the steps of mounting atleast one pair of portals on each side of the gap to be bridged and atleast one upright of substantially the same height as said portals onone side of the gap and spaced from one of the portals on that side,extending an erection cable across the gap and over the upper ends oftwo corresponding opposite portals and said upright, tightening saidcable intermediate said portals but leaving the cable portionsubstantially slack between said upright and the adjacent portal,assembling the individual elements of one frame on the groundintermediate the upright and the adjacent portal, and in a collapsedcondition with the rigid beams closely adjacent each other and theflexible chords and diagonal struts in a slack condition, attachingtrolleys to one end of each of said beams, attaching all of saidtrolleys to said cable portion, tightening said cable portion at thefree outer end thereof adjacent said upright and thereby graduallyraising the entire frame from hte ground, rolling the frame on saidtrolleys past the adjacent portal and spreading the adjacent frameelements apart intermediate said portals above said gap, drawing theouter ends of the upper chord taut and securing said ends in a fixedposition on the ground, removing the'trolleys from the frame and cable,suspending a rigid horizontal beam section on the cable, hoisting it tothe rst intersection of the upper chord with the first vertical beam anddiagonal strut, and securing it to said intersection, and successivelyhoisting other beam sections along said cable to the followingintersections and securing them thereto until a rigid horizontal beamextends across the gap to be bridged, removing said erection cable,erecting the second frame in the same manner as said first frame,bracing both frames relative to each other and to the ground, andfinally removing said uprights.

7. A method of erecting a bridge comprising erecting a pair of supportson opposite sides of a gap to be bridged for each side supporting framemember of the bridge, stretching a normally temporary cable acrosscorresponding supports from one side of said gap to the other,assembling on the ground on one side of the gap a plurality of rigidbridge verticals for each set of corresponding supporting frame members,said verticals being assembled in close side by side relation,interconnecting said verticals with flexible chord members, raising saidassembly and suspending same on said temporary cable adjacent one sideof said gap, holding one end of said assembly on one side of said gapwhile drawing the opposite end of said assembly across said gap while itis supported from said temporary cable, stretching said frame apart tospace said rigid elements apart and tighten said chord members andthereafter interconnecting the supporting frame member assemblies tocomplete the bridge structure.

References Cited in the iile of this patent UNITED STATES PATENTS140,888 Clarke July 15, 1873 1,868,630 De vou July 26, 1932 1,967,828Leake July 24, 1934 2,339,098 Nagin Jan. 11, 1944 2,376,023 Bailey May15, 1945 FOREIGN PATENTS 283,633 Italy Mar. 17, 1931 146,236 AustriaJune 25, 1936 447,143 Italy Apr. 4, 1949

